The world's biggest car maker has started a study into joined-up thinking on
transport and energy generation and management

On the day that Ed Davey, the Lib Dem energy secretary, warned of soaring energy bills to come, 67 houses in Toyota City, Nagora, Japan were generating their own.

On an overcast, humid afternoon, a roof full of Sharp photoelectric panels on just one house could barely muster a trickle of 0.7kWh, far short of the air-conditioning and lighting requirements, let alone the recharging of the battery electric car outside on the drive. But the forecast for the following day was a full seven hours of sunshine so the house's internal computer, knowing the car won't be used today, was draining its lithium-ion battery to run the air-con. Tomorrow would provide a load of free solar electricity for recharging – maybe.

Toyota's Home Energy Management (Hems) house isn't perfect. For a start, how often does a weather forecast prove itself wrong? But it is part of a gigantic eco experiment based in Toyota's dormitory town, called Ecoful Town, where a houses, cars, buses, roads and people talk to each other via a central computer about their daily energy requirements, which are then allocated in the most efficient manner.

Toyota's successful home-building department was hived off as a separate subsidiary a couple of years ago and last year it built about 15,000 homes. These three-bed HEMS equipped houses are state-of-the-art dwellings, from the more expensive part of the catalogue. They cost about €400,000 not including the lithium-ion house battery and that doesn't include the land they stand on, which is at a huge premium in Japan. They're a part of the larger study on environmental and efficient mobility, known as the low carbon society field test system, which includes 20 hydrogen filling stations to feed the thirst of fleet of fuel-cell cars that will go on sale next year, as well as 21 charging stations and hire points for a 100-strong fleet of tiny electric vehicles, plus electric bicycles and scooters, which can be hired by the hour or minute, in a similar manner to the Paris Autolib' system.

We've tested the i-Road concept, which will be part of the study, but the vast majority of electric runabouts will be COMS vehicles, a much more conventional 380kg lead-acid-battery-powered, single-seat four wheeler, with a 34-mile range and top speed of 37mph. Recharge time is six hours for a full charge and you book via a computer or smart phone and pay online with a credit card. Hire costs are £1.30 for the first 10 minutes and 13 pence a minute after that with a 0.0065p per minute loading time.

Typical journeys are about five miles and half an hour, so that'll be about £4. Toyota expects to sell about 3,000 of these monoposto runabouts a year in Japan at prices ranging from ¥700,000 (£4,515) to ¥1 million (£6,450) and the Japanese subsidiary of the 7-eleven stores has recently committed to buy 13,000 COMS vehicles over the next few years.

The key here is the data, where the vehicles go, how far, where they end and the state of their charge. It's all fed into a complex computer programme known as the Energy Date Management System (EDMS). The city fathers of Toyota City aim to link up most of the 422,000 population in the 918km² area. So EDMS garners information on weather, temperature, traffic conditions, transport availability and peak flows and provides predictions and advice to the commuters and transport companies (so more, or bigger buses can be deployed when demand spikes), as well as directing systems and people towards low-priced off-peak electricity supply.

Positive benefits for the population include transportation advice across a wide variety of modes, including trains, buses and roads, and the availability of electric vehicles and lower power bills (Toyota says that early results indicate that EDMS can save a further 20 per cent over the already green lives of the Toyota City inhabitants). Consumers also garner positive eco points (as sort of eco Green Shield Stamps), which can be used to buy eco products.

Not all of it is good, though. The idea of an outside agency draining your car's battery for a sort of Benthamite greater good might not be so great if you get invited to a surprise party, or a child becomes ill in the night. The engineers admit that in a Northern hemisphere climate such as Japan (or Britain), a more efficient way of capturing solar energy is solar water heating panels, but they're not as flexible as electric current. There's also the corrosive effect of Orwellian surveillance of the population - for this to work, Big Brother will need to know everything.

Toyota says it is managing that concern carefully through anonymisation and disposing of the data ("We have heard about your GCHQ surveillance," said one engineer with a grin). It also claims that attitudes towards sharing of energy-conservation data like this have become more positive after the stricken Fukushima nuclear power station disaster.

The company says that by mining the data it is learning valuable lessons into developing the next generation of electric cars, but despite the information the study is yielding and the claimed energy savings, it will not pay back its considerable set-up investment without the widespread adoption of similar systems in administrative areas (Prefecture) across Japan.

A much smaller study is due to commence in Grenoble, France next year when 70 i-Road and COMS electric vehicles go on test for a three-year study in how we Europeans will live with the electric car.